[QUOTE=cole;18582950]It's the SPPM that did most of the breech face cutting and I think now that these (red box CCI primers) have a cup hardness more like rifle primers.
Also, there was a small primer shortage a while back you may have missed and reloaders were running what they could get. A cheap gun (like a Glock) you actually shoot often, over time, is much, much more expensive to feed than purchase.
I seem to have heard about that shortage, but since I had already gone through a primer shortage 15+ years before that, I was well prepared for the last one.
Actually years ago, all I bought was SPPM and used them in both .357mag., 9mm, and.38spl.to consolidate to one primer type, I never had any problems like you had, or I would have stopped the use immediatly.
It didn't take long to realize that spp were cheaper and the practice of using only one primer wasn't worth it.